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World J Cardiol. Oct 26, 2014; 6(10): 1067-1079
Published online Oct 26, 2014. doi: 10.4330/wjc.v6.i10.1067
ST-segment elevation: Distinguishing ST elevation myocardial infarction from ST elevation secondary to nonischemic etiologies
Alok Deshpande, Yochai Birnbaum
Alok Deshpande, Yochai Birnbaum, The Section of Cardiology, The Department of Medicine, Baylor College of Medicine, Houston, TX 77030, United States
Author contributions: Both authors reviewed the literature and participated in writing the manuscript.
Supported by John S Dunn Chair in Cardiology Research and Education
Correspondence to: Yochai Birnbaum, MD, John S Dunn Chair in Cardiology Research and Education, The Section of Cardiology, The Department of Medicine, Baylor College of Medicine, One Baylor Plaza, MS: BCM 620, Houston, TX 77030, United States. ybirnbau@bcm.edu
Telephone: +1-713-7982735 Fax: +1-713-7980270
Received: December 29, 2013
Revised: May 20, 2014
Accepted: July 27, 2014
Published online: October 26, 2014
Abstract

The benefits of early perfusion in ST elevation myocardial infarctions (STEMI) are established; however, early perfusion of non-ST elevation myocardial infarctions has not been shown to be beneficial. In addition, ST elevation (STE) caused by conditions other than acute ischemia is common. Non-ischemic STE may be confused as STEMI, but can also mask STEMI on electrocardiogram (ECG). As a result, activating the primary percutaneous coronary intervention (pPCI) protocol often depends on determining which ST elevation patterns reflect transmural infarction due to acute coronary artery thrombosis. Coordination of interpreting the ECG in its clinical context and appropriately activating the pPCI protocol has proved a difficult task in borderline cases. But its importance cannot be ignored, as reflected in the 2013 American College of Cardiology Foundation/American Heart Association guidelines concerning the treatment of ST elevation myocardial infarction. Multiples strategies have been tested and studied, and are currently being further perfected. No matter the strategy, at the heart of delivering the best care lies rapid and accurate interpretation of the ECG. Here, we present the different patterns of non-ischemic STE and methods of distinguishing between them. In writing this paper, we hope for quicker and better stratification of patients with STE on ECG, which will lead to be better outcomes.

Keywords: Diagnosis, Electrocardiogram, Reperfusion therapy, ST segment elevation, Myocardial infarction

Core tip: At times, distinguishing between myocardial infarction with ST elevation (STEMI) from non-ischemic causes of elevation of the ST segment is difficult, especially in patients with atypical presenting symptoms. Understanding common patterns of ST elevation that are not caused by ischemia is crucial for rapid and accurate diagnosis. However, patients with baseline non-ischemic ST elevation (for example, early repolarization or repolarization changes caused by hypertrophy of the left ventricule) may develop acute myocardial infarction (true STEMI or non-ST elevation myocardial infarction with baseline ST elevation). Here we describe common patterns of non-ischemic ST elevation.